zram: cleanup zram_remove

Remove the bdev variable and just use the gendisk pointed to by the
zram_device directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220330052917.2566582-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/zram/zram_drv.c

@@ -1986,19 +1986,18 @@ static int zram_add(void)
 
 static int zram_remove(struct zram *zram)
 {
-	struct block_device *bdev = zram->disk->part0;
 	bool claimed;
 
-	mutex_lock(&bdev->bd_disk->open_mutex);
-	if (bdev->bd_openers) {
-		mutex_unlock(&bdev->bd_disk->open_mutex);
+	mutex_lock(&zram->disk->open_mutex);
+	if (zram->disk->part0->bd_openers) {
+		mutex_unlock(&zram->disk->open_mutex);
 		return -EBUSY;
 	}
 
 	claimed = zram->claim;
 	if (!claimed)
 		zram->claim = true;
-	mutex_unlock(&bdev->bd_disk->open_mutex);
+	mutex_unlock(&zram->disk->open_mutex);
 
 	zram_debugfs_unregister(zram);
 
@@ -2010,7 +2009,7 @@ static int zram_remove(struct zram *zram)
 		;
 	} else {
 		/* Make sure all the pending I/O are finished */
-		sync_blockdev(bdev);
+		sync_blockdev(zram->disk->part0);
 		zram_reset_device(zram);
 	}